What can i do with fake J201 and 2N5457's?

[abakuzam]

Hello folks, i have around 100 fake to92 J201 jfets. While i was sorting out my parts bin, i thought i should drop a question about how can i make use of them. Even they are fake maybe i can match them to make phase90? Or i can use them as input and output buffers in circuits? Also i got some fake  2N5457's , around 30 of them. I didn't have time to measure them to see how " out of spec they are". Or maybe i can use them for jfet type of switching purposes?

Have a great day/night for you all!

[duck_arse]

out of curiosity, are these fakes marked with any brandnames or logos [if yes, pictures please], or just anonymously laser etched? what about them leads you to say counterfeit?

[abakuzam]

out of curiosity, are these fakes marked with any brandnames or logos [if yes, pictures please], or just anonymously laser etched? what about them leads you to say counterfeit?

Yes , they have brand markings on them ( see the picture ) , TO-92 J201's out of production, only smd version available and i tested them out, 10 of them, all out of spec. About 2N5457's , i don't remember measuring them but, as far as i know they are out of production too, then i have time, i will measure them all and put it in some excel sheet, so we all can see the average values. Also i have smd versions of both and i just switched them in a circuit, fake ones didn't work, smd ones were bang on!

[rankot]

I have a bunch of probably fake JFET transistors, but I measure them and sort, so I can find usable ones for different roles.

[davent]

I've seen interesting jewelry, earrings made with electronic parts.
dave

[abakuzam]

I've seen interesting jewelry, earrings made with electronic parts.
dave

Maybe I should use them for necklades for my gf, perfect combination with her diode wristband

[davent]

I've seen interesting jewelry, earrings made with electronic parts.
dave

Maybe I should use them for necklades for my gf, perfect combination with her diode wristband

My wife has various pieces made with electronic bit and pieces.
dave

[stallik]

Couple of years back, I had 2 fake 201's. At least I think they were fake. I'd tried one in a Mayqueen and they didn't work until I use a 20x trimmer to bias them (by ear) and even then the sweet spot was within about 1/4 turn. I ended up with a great sounding pedal with so much bass that only some amps can handle it. I posted about it here at the time.

Just mentioning it to confirm that if you polish a turd enough, it can end up being quite shiney

[Rob Strand]

While i was sorting out my parts bin, i thought i should drop a question about how can i make use of them. Even they are fake maybe i can match them to make phase90?

It depends is they are plastic with legs, remarked BJTs, or out of spec JFETs.  Matching the JFETs should work OK.   It's not as if JFETs are precise in the first place.   You'd probably want to characterize a few to see what they really are in terms of parameters.

My wife has various pieces made with electronic bit and pieces.
dave

Wife: "What matches this top better? the 2k2 necklace or the 4k7 necklace."

[abakuzam]

Couple of years back, I had 2 fake 201's. At least I think they were fake. I'd tried one in a Mayqueen and they didn't work until I use a 20x trimmer to bias them (by ear) and even then the sweet spot was within about 1/4 turn. I ended up with a great sounding pedal with so much bass that only some amps can handle it. I posted about it here at the time.

Just mentioning it to confirm that if you polish a turd enough, it can end up being quite shiney

Well since i have a lot of that turd, it may produce something nice. I will build a test circuit, ROG Uno maybe, and test them out, that should give me the flexibility

While i was sorting out my parts bin, i thought i should drop a question about how can i make use of them. Even they are fake maybe i can match them to make phase90?

It depends is they are plastic with legs, remarked BJTs, or out of spec JFETs.  Matching the JFETs should work OK.   It's not as if JFETs are precise in the first place.   You'd probably want to characterize a few to see what they really are in terms of parameters.

They are out of spec jfets, i was able to confirm that, they are jfets. I will measure them and post my results in here. I remember that i built a okko diablo back in the day with them, it sounded okay to my untrained ears, maybe there is hope!

[Rob Strand]

They are out of spec jfets, i was able to confirm that, they are jfets

Probably usable.  Especially for controlled resistors.

[rankot]

Those that I have are really out of specs, for example, Vgs(off) is in margins for 2N5457, while Idss is corresponding to 2N5458. But I use them for different stuff and they work fine.

[abakuzam]

I measured 36 of the J201 jfets, can't find the rest of them , probably, under my bed ahah

i measured vgsoff with this : https://www.rullywow.com/jfet-matcher-project-vgsoff/

Idss with this : http://stompville.co.uk/?p=112

I used same 9v regulated power supply , these are my results:

Note: i didn't bother to put -0,xxx type of measurement for vgsoff, you can put -0, at the begining of the numbers.

Vgsoff values seems to in spec but Idss values are waay out of specsi checked my smd j201's (mmbfj201) they all seem to be in specs.

VGS(off)
Volts   Idss mA
488   1,54
522   1,15
668   1,23
424   1,23
442   1,73
460   1,42
620   1,19
698   1,51
696   1,52
618   1,24
448   1,58
406   1,3
600   1,65
452   1,45
610   1,12
625   1,31
450   1,41
485   1,16
460   1,15
436   1,64
747   1,01
637   1,76
765   1,13
424   1,17
443   1,02
589   1,07
374   1,11
585   1,51
512   1,19
451   1,18
753   1,48
365   1,82
526   1,14
490   1,3
638   1,47

[PariahBrothermann]

Make em into diodes. Connect D+S together. Unique low gain tubey clipping similar to, but not the same as using rectifier diodes for clipping. Worth a go!

[abakuzam]

Make em into diodes. Connect D+S together. Unique low gain tubey clipping similar to, but not the same as using rectifier diodes for clipping. Worth a go!

That's good idea , sounds interesting , thank you!

[PariahBrothermann]

No worries. You get a low gain od which is pretty responsive. It's my plan for the 100s of fake jfets I have. If you use a combination of fet and diode clipping, things can get pretty interesting... Good luck

[abakuzam]

No worries. You get a low gain od which is pretty responsive. It's my plan for the 100s of fake jfets I have. If you use a combination of fet and diode clipping, things can get pretty interesting... Good luck

Got any suggestions about which circuit i should try? i was thinking about replacing them in zendrive type of circuit, instead of 2n7000 , j201 could put some interesting results

[PariahBrothermann]

Zendrive sounds like a fun option... I'd suggest socketting the diodes and experimenting with different combinations. That way you can check you like it with the fets, try different diode combinations, and find the grail!

[rankot]

Vgsoff values seems to in spec but Idss values are waay out of specsi checked my smd j201's (mmbfj201) they all seem to be in specs.

If you put those values into JFET calculator on ROG, you will see that they are pretty usable for Fetzer Valve and similar circuits. Maybe out of specs, but actually really usable.

[abakuzam]

Vgsoff values seems to in spec but Idss values are waay out of specsi checked my smd j201's (mmbfj201) they all seem to be in specs.

If you put those values into JFET calculator on ROG, you will see that they are pretty usable for Fetzer Valve and similar circuits. Maybe out of specs, but actually really usable.

I appreciate it a lot, actually, i was reading that article today, so many information to learn and apply, then fail, try to debug, and learn more! That's one of the things i love about diy, failing and trying to solve problems. I'm sure that something interesting and useful will come out!